The present invention relates to a coaxial electrical portion and also to a coaxial electrical connector including such a portion, and also performing a switching function.
Numerous types of coaxial connector are already known which enable an electrical line to be connected to another electrical line when two connector portions are engaged one within the other.
Such connectors are used in particular in the field of telecommunications, specifically for connecting portable appliances such as portable telephones to test apparatus, or to an external antenna, or to electronic equipment, in particular when the portable telephone is to be used in a motor vehicle.
The Applicant company has already described such an electrical connector in U.S. Pat. No. 5,580,261, where the connector serves to provide a switching function and comprises a first connector portion having both a central conductor and a ground conductor surrounding the central conductor, being separated therefrom by an insulator, together with a third conductor which is electrically in contact with the central conductor when the connector is in the coupled state; and a second connector portion comprising both a central conductor and an outer ground conductor separated by an insulator, said second connector portion being arranged so that on coupling with said first connector portion, it separates the central conductor and the third conductor of the first connector portion and puts the central conductors of the two connector portions into contact with each other.
That document provides for the major fraction of the length of the third conductor of the first connector portion to be separated from the central conductor of said connector portion by the ground conductor.
In another embodiment described in U.S. Pat. No. 5,453,019, the central conductor and the third conductor of the first connector portion are formed by two conductive springs bearing against each other when the connector is in the uncoupled position, and during coupling of the connector portions the central conductor of the second connector portion bearing against an extension of the insulation provided in said second connector portion then engages between the two conductive springs, thereby moving them apart.
In practice, the first connector portion can be a socket mounted on a printed circuit card and the second connector portion can be a plug mounted at the end of a coaxial cable and suitable for engaging in the socket.
Given the dimensions required by known structures, the socket-forming first connector portion is mounted on the printed circuit card in a xe2x80x9ccard edgexe2x80x9d configuration, i.e. the axis of the socket is parallel to the card.
For reasons of accessibility, it is desirable to be able to mount the socket-forming connector portion perpendicularly to the printed circuit card, as is the case for the coaxial connector described in JP-A-125 410, thereby reducing the height available for the connector portion in the article (such as the portable telephone) in which it is mounted.
In practice, known coaxial electrical connectors cannot be miniaturized as much as is desired while still being of low cost design, in particular because of the structure of the plug-forming second connector portion, in particular given the arrangement of its central conductor and the insulation which holds the central conductor. As a result, known coaxial connectors have a complementary connector portion forming a socket of size that is relatively large, in particular in the axial direction.
The present invention proposes making a coaxial electrical connector portion that can be used in particular in a coaxial electrical connector that also, performs a switching function, in a manner that enables a high degree of miniaturization to be achieved while being low cost in design, by providing a novel embodiment of the central contact. In addition, the connector portion of the invention, when used with a switching complementary connector portion, ensures excellent radio frequency (RF) isolation between the two electrical lines to be switched.
The present invention provides a coaxial electrical connector portion comprising a central conductor and an outer body forming a ground contact, made of a conductive material or coated in a conductive material, defining a cylindrical inside cavity, the connector portion being characterized by the fact that the central conductor is a metallized track made on one face of a printed circuit insert, the insert preferably being in the form of an elongate rectangle and held inside said body by being disposed diametrically across said cavity, the printed circuit insert including, in addition to said metallized track forming the central contact, at least one metallized zone made on the face of the insert opposite from its face carrying said track and/or on the face carrying said track, the metallized zone(s) being electrically connected to ground and being in contact with the body of said connector portion.
The connector portion of the invention thus has two electromagnetically isolated cavities, one conveying the signal and the other performing the function of providing isolation relative to electromagnetic radiation.
The track forming the central contact in the invention itself constitutes a microwave transmission line relative to the metallized zone(s) in contact with ground.
The printed circuit insert is preferably held inside the body by being engaged in diametrically opposite grooves of the inside wall of an extension of tapering section of said body.
The connector portion can be straight or angled in shape.
The present invention also provides a coaxial electrical connector enabling a switching function to be performed, the connector comprising a first connector portion comprising two central conductive springs bearing against each other in the uncoupled position of the connector, and an outer ground conductor surrounding said springs and being separated therefrom by insulation, the connector being characterized by the fact that its second connector portion comprises a connector portion as defined above, making it possible, on coupling with the first connector portion, to-separate said springs thereof from each other, making electrical contact with one of said springs constituting the central conductor of the first connector portion and the conductive metallized track forming the central conductor of the second connector portion.